Study of Direct Photon plus Jet production in CMS Experiment at \sqrt{s}=14 TeV

Abstract

We present simulation results of $\gamma$ + Jet analysis using CMS (Compact Muon Solenoid) Object-Oriented software at the Large Hadron Collider (LHC) center of mass energy $\sqrt{s}$=14 TeV. The study of direct photon production helps in validating the perturbative Quantum Chromodynamics (pQCD) and providing information on the gluon distribution in the nucleons. Direct photon processes also constitute a major background to several other Standard Model (SM) processes and signals of new physics. Thus these processes need to be understood precisely in the new energy regime. In this work, we have done a detailed study of the GEANT4 simulated $\gamma$ + jet events generated with Pythia, and the related background processes. Isolation cuts have been optimized for direct photon which improves the signal over background ratio by $\sim 25$ as compared to previous studies done in CMS. The inclusion of a large $\Delta \varphi$ cut between the photon and the leading jet at $40^0$ in the analysis leads to a further increase of $\sim 15$ in S/B, thus giving an overall gain of $\sim 42$ in S/B ratio.

20 Pages, 13 Figures. Accepted in European Journal of Physics C

References in corpus (2)

• On the application of 'photon+jet' events for setting the absolute jet energy scale and determining the gluon distribution at the LHC
• On the Possibilities of Measuring the Gluon Distribution Using 'photon/Z^0+jet' Events at Tevatron Run II and LHC

Cited by in corpus (7)

• Direct photons as probes of low mass strings at the LHC
• Photon - Jet Correlations and Constraints on Fragmentation Functions
• Quark Excitations Through the Prism of Direct Photon Plus Jet at the LHC
• LHC Phenomenology of Lowest Massive Regge Recurrences in the Randall-Sundrum Orbifold
• String Physics at the LHC
• Particle Phenomenology of Gravitational Events at the TeV Scale
• Prompt photon production in photoproduction, DIS and hadronic collisions